The present invention relates to a mobile tracking unit capable of detecting defective conditions in railway vehicle wheels and railtracks and, more particularly, to a mobile tracking unit employing a motion sensor for sensing such defective conditions.
Wear on the treads of railway vehicle wheels is a well-known phenomenon which can cause any given wheel to have a pronounced flat section. A defective railway vehicle wheel condition, as characterized by a wheel having such flat section, is referred herein as a "flat wheel" condition. The occurrence in a rail or train vehicle of such "flat wheel" condition or defect is undesirable due to potential for cargo damage as well as increased operating costs and reduced safety while the railway vehicle is travelling. Wear on bearings which support the railway vehicle wheels can induce similar undesirable results. It is desirable to provide a technique which allows for determining the presence of such defects in a manner which uses relatively few components so as to enhance operational reliability and minimize electrical power consumption and weight requirements. Further, it is desirable to provide a technique which allows for detecting defective conditions associated with the railtrack upon which a given railway vehicle travels. This information is particularly useful to those responsible for maintaining the railtracks of the nation in good operating condition. In addition, it is desirable to provide a mobile tracking unit which is capable of implementing the foregoing techniques and which can readily provide the location of the railway vehicle. Typically, the mobile tracking unit includes a navigation set, such as a Global Positioning System (GPS) receiver or other suitable navigation set, responsive to navigation signals transmitted by a set of navigation stations which can be either space- or earth-based. In each case, the navigation set is capable of providing data indicative of the vehicle location based on the navigation signals. The mobile tracking unit can include a suitable electromagnetic emitter for transmitting the vehicle position data and other data acquired with sensing elements in the vehicle to a remote location. It will be appreciated that the mobile tracking unit advantageously allows for determining the location at which any particular defect occurs.